Vehicle door latch mechanism



Feb. 18, 1964 A. J. D! SALVO ETAL 3,121,580

VEHICLE DOOR LATCH MECHANISM Filed June 9, 1961 2 Sheets-Sheet 1 ANTHON) J DIS/4L v0 MAURICE M. WES TERDAL E INVENTORS BY M A TTOE'NE'VS1964 A. J. DI SALVO ETAL 3,121,580

VEHICLE DOOR LATCH MECHANISM Filed June 9, 1961 2 Sheets-Sheet 2 NA 3949 47 F/G4 A N THON) J 01.54 L V0 MAUR/C E M. WES TE RDAL E IN VENTORSBY Q/ wl United States Patent 3,121,589 VEHECLE DGQR LATQE MECHANISMAnthony 5. Bi alvo, Allen lark, and Maurice M. Westerdale, ln' ter,Mich., assignors to Ford Motor Company, Dearhorn, Mini 1., a corporationof Delaware Filed June 9, 1961', filer. No. 116,0(l3 5 Ciaiins. (Cl.292-229) This invention relates to latch mechanisms for swinging doors,especially the doors of automobile or other vehicle bodies.

Most door latch mechanisms currently in use on passenger motor vehiclescomprise a rotatable or pivotable latch device adapted to en age astriker or keeper device mounted on a vehicle door framing structure, adetent means releasably engaged with the latch device to hold the latterin door latched position, an actuating or release lever operativelyassociated with the detent means for disengaging the same from the latchdevice, and manually operable means accessible from the outside andinside of the vehicle door operative to cause disengagement of thedetent means. In almost all latch mechanisms of this general class, themanually operable means operative from the outside of the door acts onthe detent means through the actuating or release lever. The manuallyoperable means operative from the inside of the door may be constructedand arranged to act directly on the detent means or through theactuating or release lever, depending on whether or not it is desired tohave a latch mechanism which cannot be rendered inoperative from theinside of the vehicle. Most vehicles are provided with at least one doorwhich can always be opened from the inside of the passenger compartmenteven if the latch mechanism is conditioned so that the door cannot beopened from the outside.

Latch mechanisms may be categorized by the manner in which the manuallyoperable means is rendered inoperative to disengage the detent meansfrom the latch device to place the latch mechanism in locked condition.This may be done by the use of a blocking means selectively positionableto block movement of the detent means actuating or release lever. Thismay also be done by use of a disconnection means interposed in the trainof members extending from the manually operable means to the detentmeans.

Reference may be made to US. Patent No. 2,987,336, issued June 6, 1961,for a latch mechanism exemplifying the type in which a blocking means isused to render the manually operable means inoperative to disengage thedetent means from the latch device.

it is an object of the present invention to provide a latch mechanismcharacterized by many of the features of the latch mechanism disclosedin the above-mentioned patent and which is further characterized by theinclusion of features by which the means manually operable from theoutside of the door, such as the handle, push button or like operatedmeans, may be operatively disconnected from the detent actuator orrelease lever.

More specifically, in the latch mechanism embodying the presentinvention, the train of parts or members operatively associating thehandle, push button or the like to the detent means includes a part ormember directly coupled to the detent means but being shiftable thereonfrom a detent actuating to a detent non-actuating position. This part ormember is shiftable by a locking lever operable from either the outsideor the inside, or both, of the door. A latch mechanism so constructed issaid to have a free wheeling handle, push button or the like asdistinguished from a blocked type. In other words, the handle, pushbutton or the like is always responsive to finger pressure regardless ofwhether or not the latch Patented Feb. 18, 1964.-

in mechanism is in locked or unlocked condition, even though movement ofthe handle, push button or the like in locked condition of the latchmechanism is not effective to cause disengagement of the detent meansfrom the latch device.

Probably the major advantage to be derived from socalled free wheelingtype latch mechanisms is that the latch mechanism parts, particularlythose in the train of elements between the outside operator and thedetent means, may be made of much lighter gauge metal than the partsused in a blocked type lock. The reason is that in a blocked type lock,the parts must be made strong enough to withstand any force which mightbe exerted on the outside operator by means of a pry bar, hammer orother device which may be used when it is attempted to break or make aforceful entry through the door when the door is in locked condition. Itwill be readily apparent that in a latch mechanism where part of thetrain of elements is disconnected, any force exerted on the handle, pushbutton or the like by an implement of any kind is ineiiective to distortor spring the latch mechanism parts to a degree sufficient to causedisengagement of the detent from the latch device so as to permit thedoor to be opened. This, of course, applies to any impact the handle,push button or the like might sustain in a collision or upset of thevehicle. The use of light gauge metal results in a cost saving in themanufacture of the latch mechanism. Less metal is used and the life ofthe die for stamping the parts is much longer with light gauge metal.

Other objects, advantages and features of the present invention will bemade more apparent as this description proceeds, reference being had tothe accompanying drawings, wherein:

FIG. 1 is an elevational view of the latch mechanism as it appears fromthe inside of the vehicle door;

FIG. 2 is a fragmentary view in part similar to P16. 1 illustratingparts of the latch mechanism in an operative position different fromthat shown in FIG. 1;

FIG. 3 is an elevational view in part sectional taken from the rightside of FIG. 1; and

FIG. 4 is an enlarged sectional view taken on the line 4-4 of FIG. 1.

In the drawings there is illustrated, by way of example, a preferredembodiment of the present invention as applied to the doors and doorframe structures of an automobile body. Adapted to be secured as bymeans of screws (not shown), to the inner side of the free edge wall ofa vehicle door is a case plate 31 having a flange 12 which is adapted tobe positioned along the inner panel of the door. The present latchmechanism has a pair of pivoted latch devices comprising jaw elements 13(see FIG. 3) positioned at the outer face of the case plate 11. As bestseen in FIG. 3, each jaw element 13 is provided with an integral stud orpivot shaft 14 having a reduced bearing portion 16 extending through anaperture in the case plate, the aperture having a flanged edge 17providing bearing support for the bearing portion -16. In FIG. 3, aWasher 18 is shown interposed between the case plate 1'1 and the mainbody portion of the stud shaft 1d. The inner reduced end or bearingportion 16 of the stud shaft is provided with longitudinally extendingfiats 19 thereon. Fitted over the reduced end or bearing portion 16 andkeyed thereto by the flats 19 are a pair of control plates 21 and 22,respectively. From the foregoing, it is apparent that each jaw element13 is rigid'iy coupled to a control piste 2.1 and 22, respectively,being concentric therewith on a stud shaft 1.4. As defined herein, eachlatch device thus comprises a jaw element '13, a stud shaft or pivot 14and a respective control plate ill or 22.

Each jaw element 13 is a substantially triangular plate member havingits pivot axis located near the apex end. The base or side 23 oppositethe apex end is outwardly rounded and is provided in the center thereofwith a semicircular recess or enlarged notch 24.

Each control plate is a gear sector having teeth 26, the teeth beingintermeshed to thereby couple the control plates together for correlatedmovement. Thus, both jaw elements 13 are controlled for movement inunison in counterdirections of swinging movement toward and from eachother into and out of door latched condition. A spiral spring 27 isdisposed substantially coaxially or concentric with and adjacent theinner face of the control plate 21. The spring 27 has its inner end 28operatively connected to the stud shaft 14 carrying the control plate21, the stud shaft having a diagonal slot or kerf 29 receiving thespring end. The outer or free end 31 of the spring 27 is looped over theedge of a notch 32 in the case plate flange 12. The spring 27 isinstalled in a wound up or preloaded condition so that at all times ittends to rotate control plate 21, shaft 14 and jaw element 113associated therewith in a counterclockwise direction as viewed inFIG. 1. Since the control plate 22 is coupled to the control plate 21through the gear teeth 25, rotative force exerted by the spring 27 onthe plate 21 is transmitted to the plate 22 so that it, at all times, isunder rotative force tending to rotate it, shaft 14 and jaw element 13associated therewith in a clockwise direction as viewed in FIG. 1.

The control plate 22 is provided with two peripherally spaced abutmentsor ratchet teeth 33 and 34, respectively. Cooperable with the abutmentor ratchet toothed edge of the control plate 22 is a swinging detent,pawl or dog 35 pivotally mounted on a shoulder rivet 36 secured to thecase plate 11. It will be noted that the detent 35 extends in asubstantially horizontal direction across the case plate 11 and ispivoted intermediate its ends. At one'side of the pivot axis, the rightside as viewed in FIG. 1, the detent is provided with an abutmentportion 3'7 extending in a substantially upward direction and cooperablewith the teeth or abutments 33 and 34 on the control plate 22. When thedetent abutment 37 is in engagement with the control plate abutment 33,the jaw elements 13 will be in a safety latched position. When theabutment .37 is in engagement with the latched control plate abutment34, as shown in FIG. 1, the jaw elements l3 will be in final latchedposition, as will be more fully explained. To the right of its pivotaxis 36, the detent 25 is provided with an extension 38 and to the leftof its pivot axis it is provided with an enlarged stepped or embossedportion 39. The enlarged portion 39 of the detent has a substantiallyL-shaped slot 41 therein. The slot 41 has two sections, section 42extending radially of the pivot axis 3% and section 43 extendingupwardly from the irmer end of the section 42 and circumferentiallyrelative to the pivot axis 36. Extending through the slot 41, is astepped cylindrical bearing or bushing m mber, generally designated 44-.The bushing is preferably made of a low friction coefficient material,such as one of the nylon or Teflon plastics used for bearing or bushingdevices. As best seen in FIG. 4, the bushing 4 lhas an enlarged headportion 45 at one end thereof and a smaller diameter cylindrical portionwhich slidably fits through the slot 41. On the end opposite theenlarged head portion 45 of the bushing, the cylindrical portion 4-6 isencompassed by one end 4-7 or" a link A Washer .9 is interposed betweenthe inner surface of the link 47 and the surface of the detent portion3%. The link end 47 is retained on the bushing by a shoulder 51. Thebushing 44 has a longitudinally extending aperture 52 therethrough. Atthe end of the bushing opposite its head end, the aperture 52 isintersected by a semicircular recess 53 having lip portions 2- creatinga restricted entrance to the recess.

The recess 5'3 and the longitudinally extending hole 52 are adapted toreceive the L-shaped end 55 of a link or rod 56 connecting the bushing4-4 to a bell crank lever 57 pivotally supported on a bracket 53 at theupper part of the vehicle door (not shown). The bracket 58 may be anintegral part of a door handle assembly or otherwise mounted within thedoor. The lever 57 has a depending flange portion 59 which lies in thepath of the plunger or stem till which forms an extension of aconventional push button mounted in a door handle accessible from theoutside of the vehicle door.

Referring now to FIG. 2, the bushing 44 is illustrated as being at theextreme outer end of the radially extending section 52 of the slot 41 inthe end 39 of the detent 35. Upon the door handle push button beingdepressed so that its stem 61 moves toward and engages the flange 59 onthe bell crank lever 57, the bell crank lever 57 will be swung in acounterclockwise direction raising the link 57 and also the bushing 44.But since the bushing 44 is held against upward movement relative to thedetent by its relationship to the slot section 42, the movement of thelink 56 is transmitted to the detent 35 cansing the latter to be swungin a clockwise direction as viewed in the drawings. It will be readilyapparent that this will cause the abutment 37 on the detent 35 to moveout of the path of the abutments 34 and 33 on the latch control plate22. This permits the spring 27 to urge the jaw elements toward unlatchedcondition and thereby permit-ting the vehicle door to be opened.

Referring now to P16. 1, it will be noted that the bushing is shown atthe inner end of the section 42 of the slot 4d or in position to move inthe circumferential sec tion 43 of the slot 41. Under this condition,upward movement of the link 56 through actuation of the bell crank lever57 is eliective to raise the bushing 44. The latter, however, movesfreely relative to the detent 35 and the latter is thereby maintained ina relationship such that its abutment 37 blocks movement of the controlplate 22.

The position of the bushing 44 is controlled through a locking lever 62pivotally mounted intermediate its ends on a pivot stud 63 secured tothe case plate 11. At its left end, as viewed in the drawings, thelocking lever 62 is provided with a stepped or embossed upwardlyextending appendage 64. The above-mentioned link 48 is pivotallyconnected at its end 65 to the appendage 64. The locking lever 62 actingthrough the link 48 controls the position of the bushing 44 relative tothe radially and ci-rcumfe-rentially extending sections 42 and 43,respec tively, of the slot 41 in the detent 35. As shown in FIG. 1, theleft end of the blocking lever 62 is in a raised position and the link48 has pulled the bushing 44 toward the right or into thecircumferentially extending section 43 of the slot 41. Upon the lockinglever being swung in a counterclockwise direction so that its left endis lowered, the link 48 will push the bushing 44 downwardly and into theextreme outer end of the section 42 of the slot 41, thus placing it in aposition to transmit movement of the link 56 to the detent 35.

It will be noted that the detent 35 has a downwardly extending part 66which is adapted to abut a projection 67 of the locking lever. Thisabutting relationship serves two functions: First, it provides a stoplimiting the extent to which the locking lever may be swung in acounterclockwise direction. Further, when the latch control plate 22 isin its unlatched position, the surface 63 of the abutment 33 willoverlie the corner of the abutment 37 on the dentent. This prevents thelatter from moving into a fully latched position relative to the controlplate 22. As a result, the portion 66 of the detent 35 will bepositioned somewhat below its position shown in FIGS. 1 and 3 and willobstruct upward movement of the portion 67 of the locking lever 62. Thisprevents the latter from being swung so as to fully raise its appendage64. The degree of movement is such that the bushing 44 will not come outof the section 42 of the slot 41, and the latch mechanism can thus notbe placed in latch locked or free wheeling condition. The relationshipof the parts is such 55 that the latch mechanism can only be placed inlatched locked or free wheeling condition when the door is closed andthe jaw elements fully encompass the striker or keeper device with whichthey coact to maintain the door in a latched condition.

The locking lever 62 is adapted to be swung from nonlocking positioninto locking position in a conventional manner either from the inside orthe outside of the vehicle door. For actuation from the inside of thedoor, the end of the locking lever 62 to the right of the pivot axis 63is provided with an aperture 69 therein to receive the end of a rod (notshown) provided with an access button (not shown) located on the innerside of the door panel in an accessible location. For actuation from theoutside of the door, the locking lever 62 is provided at the other sideof its pivot axis with a slotted flange 71 located bencath the appendage6 This flange '71 is adapted to receive the crank end of a shaft (notshown) coupled to a conventional key operated mechanism accessible fromthe outside of the vehicle door in a manner well-known in the art.

The locking lever 62 is yieldably held and urged toward its limits ofmovement by means of a snap-over or toggle spring 72 of suitablestrength attached at one end to the locking lever 62 and at its otherend to the case plate 11. As was stated above, the limit of movement ofthe locking lever 62 in a clockwise direction is controlled by theabutment portion 66 of the detent 35. The movement of the locking leverin a counterclockwise direction is controlled by the position of thebearing 44 in the end portion of the slot section 42, the toggle springthus being effective to ensure that the bushing 44 is urged fully to theleft of the end section 42 of the slot as viewed in FIG. 2.

The present latch mechanism is preferably operated from the inside ofthe door through the medium of a remote control mechanism comprising alongitudinally shiftable drag link 73 which is pivotally connected tothe lower end 74 of a bell crank lever 75 (see FIG. 3). The bell cranklever 75 is pivoted on the shank of a shoulder rivet 76 secured to thecase plate flange 12. The bell crank lever 75 is provided with anangularly upwardly extending arm 77 adapted to overlie the extension 38on the end of the detent means 35. Upon the bell crank lever being swungin a clockwise direction as viewed in FIG. 3, it will engage theextension end 38 of the detent 35 cansing the latter to be swung in aclockwise direction out of engagement with the ratchet teeth abutments33 and 34. It should be noted that actuation of the detent 35 throughthe remote control bell crank lever '75 is independent of actuation bythe outer manually operable means. Thus, even if the outside operator isrendered inoperative to disengage the detent from the latch device, thedetent can always be disengaged from the latch device from the inside ofthe vehicle through actuation of the remote control mechanism.

The detent 35 is urged into latching engagement with the ratchet teethabutments 33 and 34 by a coil spring "73 having its inner end held in aker f or slot 79 in the pivot stud 36 mounting the detent 35 on the caseplate 11. The spring 78 is provided with a horizontally extending freeend portion 81 which overlies an edge of the step or embossment 39 inthe detent. The free end portion 81 of the spring extends further so asto also overlie the path of upward movement of the bushing 44. Thepurpose of this is to ensure that the bushing 44 will not befrictionally caught in the upper end of the section 43 of the slot 4-1,but will always be urged toward the lower end of the section 43 of theslot. Thus, when the link 56 is raised with the bushing 44 in the freewheeling position, and the link is then released upon release of thepush button extension 61 from hearing engagement with the flange h onthe bell crank 57, the bushing will be restored to the intermediateposition shown in FIG. 1 Where it is in position to be urged toward thesection 42 of the slot 41 upon restoration of the locking lever tononlocking position.

The manner in which the jaw elements 13 are adapted to coact with astriker or keeper device, generally designated 72, as seen in FIG. 3, isfully described in the abovementioned U.S. Patent 2,987,336.Accordingly, reference is made to that patent for these details.

It will be understood that the invention. is not to be limited to theexact construction shown and described, but that various changes andmodifications may be made without departing from the spirit and scope ofthe invention as defined in the appended claims.

We claim:

1. A latch mechanism for a door comprising:

a support plate for disposition at a free edge wall of the door,

latch device means pivotally mounted on said support plate for movementbetween latched and unlatched positions,

a detent pivotally mounted on said support plate and having an abutmentin engagement with an abutment on said latch device means for holdingthe same in door latched position,

an outer manually operable means including a first link means,

a bushing means coupling said first link means to said detent,

said bushing means projecting through a slot in said detent,

said slot having two sections,

one of said sections extending radially and the other of said sectionsextending circumferentially relative to the pivot axis of said detent,and

a locking lever pivotally mounted on said support plate,

a second link means coupling said locking lever to said bushing means,

said locking lever being operable through said second link means to movesaid bushing means from said radial to said circumferential section ofsaid slot or vice versa,

said bushing means when positioned in said radial section beingoperative to transmit movement of said first link means occasioned byoperation of said outer manually operable means to said detent topivotally move the same to disengage said detent abutment from saidlatch device abutment and when in said circumferential section of saidslot being freely movable with said first link means upon movement ofthe latter occasioned by operation of said outer manually operable meanswithout causing movement of said detent.

2. A latch mechanism for a swinging door comprising:

a support plate for disposition at a free edge wall of the door,

latch device means pivotally mounted on said support plate for movementbetween latched and unlatchcd positions,

a detent pivotally mounted on said support plate for pivotal movementabout a pivot axis parallel to the pivot axis of said latch device meansand having at one side of its pivot axis an abutment in engagement withan abutment on said latch device means for holding the same in doorlatched position,

outer manually operable means including a first link means,

a bushing means coupling said first link. means to said detent,

said bushing means projecting through a slot in said detent at theopposite side of the pivot axis of the latter,

said slot having a first section which extends radially and a secondsection which extends circumierentiah ly relative to the pivot axis ofsaid detent, and

a locking lever pivotally mounted on said support plate for pivotalmovement about a pivot axis parallel to the pivot axes of said latchdevice means and detent,

s,121,sse

said detent being interposed between said latch device and lockinglever,

a second link means coupling said locking lever to said bushing means,

said locking lever being operable through said second link means to movesaid bushing means from the radial to the circumferential section ofsaid slot or vice versa,

said bushing means when positioned in the radial section being operativeto transmit movement of said first link means occasioned by operation ofsaid outer manually operable means to said detent to pivotally move thesame to disengage said detent abutment from said latch device abutmentand when in the circumferential section of said slot being free lymovable with said first link means upon movement of the latteroccasioned by operation of said outer manually operable means Withoutcausing movement of said detent.

3 A latch mechanism for a swinging door comprising:

a support plate for disposition at a free edge wall of the door,

latch device means pivotally mounted on said support plate for movementbetween latched and unlatched positions,

a detent pivotally mounted on said support plate and having at one sideof its pivot axis an abutment in engagement with an abutment on saidlatch device means for holding the same in door latched position,

outer manually operable means including a first link means,

a bushing means coupling said first link means to said detent,

said bushing means projecting through a slot in said detent at theopposite side of the pivot axis of the latter,

said slot having two sections,

one of said sections extending radially and the other of said sectionsextending circumferentially relative to the pivot axis of said detent,and

a locking lever pivotally mounted on said support plate,

the pivot axes of said latch device means, detent and locking leverbeing parallel and said detent being interposed between said latchdevice means and said locking lever,

a second link means coupling said locking lever to said bushing means,

said locking lever being operable through said second link means to movesaid bushing means from said radial to said circumferential section ofsaid slot or vice versa,

said bushing means when positioned in said radial section beingoperative to transmit movement of said first link means occasioned byoperation of said outer manually operable means to said detent topivotally move the same to disengage said detent abutment from saidlatch device abutment and when in said circumferential section of saidslot being freely movable with said first link means upon movement ofthe latter occasioned by operation of said outer manually operable meanswithout causing movement of said detent,

said latch device means when in unlatched position abutting said detentand displacing the latter into a locking lever blocking position andpreventing movement of said bushing to said circumferential section ofsaid slot.

4. A latch mechanism for a swinging door comprising,

a support having a main plate portion for disposition at the free edgewall of the door,

a pair of jaw elements pivotally mounted on one side of said plateportion for swinging movement about spaced axes perpendicular to theplane thereof,

a pair of control members mounted on the opposite side of said plateportion,

each control member being fixedly coupled to one of said jaw elementsfor pivotal movement th rewith,

said control members having intermeshed portions whereby said jawelements are controlled for movement in unison toward and from eachother to door latched and door unlatched positions, respectively,

at least one of said control members being provided with a detent enageable portion,

a detent pivotally mounted on said support plate and having at one sideof its pivot axis an abutment engageable wtih said detent engageaoleportion for holding said jaw elements in door latched position,

outer manually operable means mounted on said support,

said outer manually operable means including a first link means,

a bushing means coupling said first link means to said detent,

said bushing means projecting through a slot in said detent at theopposite side of the pivot axis of the latter,

said slot having a first section extending radially and a second sectionextending circumferentially relative to said detent pivot axis, and

the pivot axes of said control member, detent and locking lever beingparallel and said detent being interposed between said one controlmember and said locking lever,

a second link means coupling said locking lever to said bushing means,

said locking lever being operable through said second link means to movesaid bushing means from said radial to said circumferential section ofsaid slot or vice versa,

said bushin means when positioned in said radial sec tion beingoperative to transmit movement of said first link means occasioned byoperation of said outer manually operable means to said detent topivotally move the same to disengage said detent abutment from saiddetent engageable portion of said one control member and when in saidcircumferential section of said slot being freely movable with saidfirst link means upon movement of the latter occasioned by operation ofsaid outer manually means without causing movement of said detent,

said latch device means when in unlatcbed position abutting said detentand displacing the latter into a locking lever blocking position andpreventing movement of said bushing to said circumferential section ofsaid slot.

5. A latch mechanism for a swinging door comprising,

a support having a main plate portion for disposition at the free edgewall of the door,

a pair of jaw elements pivotally mounted on one side of said plateportion for swinging movement about spaced axes perpendicular to theplane thereof,

a pair of control members mounted on the opposite side of said plateportion,

each control member being fixedly coupled to one of said jaw elementsfor pivotal movement therewith,

said control members having intermeshed portions whereby said jawelements are controlled for movement in unison toward and from eachother to door latched and door unlatched positions, respectively,

at least one of said control members being provided with a detentengageable portion,

a detent pivotally mounted on said support plate and having at one sideof its pivot axis an abutment engageable with said detent engageableportion for holding said jaw elements in door latched position,

outer manually operable means mounted on said support, said outermanually operable means including a first link means,

a bushing means coupling said first link means to said detent,

said link means having an end portion passing through the center of saidbushing means,

said bushing means projecting through a slot in said detent at theopposite side of the pivot axis of the latter,

said slot having a first section extending radially and a second sectionextending circumferentially relative to said detent pivot axis, and

the pivot axes of said control member, detent and locking lever beingparallel and said detent being interposed between said one controlmember and said locking lever,

a second link means coupling said locking lever to said bushing means,

said second link means comprising a link which at one end thereofcircumferentially encompasses said bushing means and which at the otherend thereof is pivotally connected to said locking lever,

said locking lever being operable through said second link means to movesaid bushing means from said radial to said circumferential section or"said slot or vice versa,

said bushing means when positioned in said radial scction beingoperative to transmit movement of said first link means occasioned byoperation of said outer manually operable means to said detent topivotally move the same to disengage said detent abutment from saiddetent engageable portion of said one control member and when in saidcircumferential section of said slot being freely movable With saidfirst link means upon movement of the latter occasioned by operation ofsaid outer manually operable means Without causing movement of saiddetent,

said latch device means when in unlatched position abutting said detentand displacing the latter into a locking lever blocking position andpreventing movement of said bushing to said circumferential section ofsaid slot.

References Cited in the file of this patent UNITED STATES PATENTS2,236,702 Andersen Apr. 1, 1941 2,782,062 Smith Feb. 19, 1957 2,903,285Roethel Sept. 8, 1959 2,987,336 Kramer June 6, 1961

1. A LATCH MECHANISM FOR A DOOR COMPRISING: A SUPPORT PLATE FORDISPOSITION AT A FREE EDGE WALL OF THE DOOR, LATCH DEVICE MEANSPIVOTALLY MOUNTED ON SAID SUPPORT PLATE FOR MOVEMENT BETWEEN LATCHED ANDUNLATCHED POSITIONS, A DETENT PIVOTALLY MOUNTED ON SAID SUPPORT PLATEAND HAVING AN ABUTMENT IN ENGAGEMENT WITH AN ABUTMENT ON SAID LATCHDEVICE MEANS FOR HOLDING THE SAME IN DOOR LATCHED POSITION, AN OUTERMANUALLY OPERABLE MEANS INCLUDING A FIRST LINK MEANS, A BUSHING MEANSCOUPLING SAID FIRST LINK MEANS TO SAID DETENT, SAID BUSHING MEANSPROJECTING THROUGH A SLOT IN SAID DETENT, SAID SLOT HAVING TWO SECTIONS,ONE OF SAID SECTIONS EXTENDING RADIALLY AND THE OTHER OF SAID SECTIONSEXTENDING CIRCUMFERENTIALLY RELATIVE TO THE PIVOT AXIS OF SAID DETENT,AND A LOCKING LEVER PIVOTALLY MOUNTED ON SAID SUPPORT PLATE, A SECONDLINK MEANS COUPLING SAID LOCKING LEVER TO SAID BUSHING MEANS, SAIDLOCKING LEVER BEING OPERABLE THROUGH SAID SECOND LINK MEANS TO MOVE SAIDBUSHING MEANS FROM SAID RADIAL TO SAID CIRCUMFERENTIAL SECTION OF SAIDSLOT OR VICE VERSA, SAID BUSHING MEANS WHEN POSITIONED IN SAID RADIALSECTION BEING OPERATIVE TO TRANSMIT MOVEMENT OF SAID FIRST LINK MEANSOCCASIONED BY OPERATION OF SAID OUTER MANUALLY OPERABLE MEANS TO SAIDDETENT TO PIVOTALLY MOVE THE SAME TO DISENGAGE SAID DETENT ABUTMENT FROMSAID LATCH DEVICE ABUTMENT AND WHEN IN SAID CIRCUMFERENTIAL SECTION OFSAID SLOT BEING FREELY MOVABLE WITH SAID FIRST LINK MEANS UPON MOVEMENTOF THE LATTER OCCASIONED BY OPERATION OF SAID OUTER MANUALLY OPERABLEMEANS WITHOUT CAUSING MOVEMENT OF SAID DETENT.